Air in a room includes a variety of substances which may be undesirable or harmful to the human body, such as dust, pollen, cigarette smoke, and exhaled breath. Particularly in recent years, the harmful substances tend to accumulate in a room due to increased air tightness of a house. Thus, in areas with serious air pollution, or at homes, offices and the like with people suffering from pollen allergy, it is difficult to naturally ventilate a room by opening windows, which has resulted in widespread use of air purifiers having the function of cleaning air by a filter that purifies the air in a room.
Air purifiers having a humidifying function have also been commercialized for adjusting the humidity of air to be more comfortable while purifying the air. In such an air purifier, the air purified by passing through a filter unit is further humidified by passing through a humidification filter.
Such an air purifier including a humidification filter is disclosed in Japanese Patent Laying-Open No. 2013-78719 (PTD 1), Japanese Patent Laying-Open No. 2013-72584 (PTD 2), Japanese Patent Laying-Open No. 2013-70793 (PTD 3), and Japanese Patent Laying-Open No. 2013-57507 (PTD 4). Japanese Patent Laying-Open No. 2007-208981 (PTD 5) discloses a technique of an infrared light emitting device for use in electrical equipment. Japanese Patent Laying-Open No. 09-122421 (PTD 6) discloses a technique of an air filter and its applied equipment.